Carotid remodeling of hypertensive subjects and polymorphism of the angiotensin-converting enzyme gene

Background This study was designed to investigate the relationships between changes in the structure and function of carotid arteries and angiotensin converting enzyme (ACE) gene polymorphism in Chinese hypertensive subjects. Methods Multiplex polymerase chain reaction amplification was used to evaluate the ACE gene insertion/deletion (I/D) polymorphism. High-resolution B-mode ultrasound examinations were performed to detect parameters of carotid artery remodeling. Results Intima-media thickness (IMT) was significantly different among the DD, ID and II genotypes of ACE (DD>ID>II, P <0.05). Carotid internal diameter,distensibility and stiffness were similar among the DD,ID and II genotypes of ACE ( P >0.05) in hypertensive subjects. The frequency of the DD gene and D allele of ACE were higher in patients with thickening carotid than in patients with normal carotid (70.4% vs 24.1%,and 79.5% vs 40.5%,respectively, P <0.001). In multiple stepwise regression analysis,independent risk factors for increased carotid IMT in hypertensive subjects were ACE genotypes ( P <0.001),age ( P <0.001) and carotid internal diameter ( P =0.032). Moreover,triglycerides and total cholesterol were higher in patients with the DD genotype than in those with the II genotype ( P <0.05). Conclusions The I/D polymorphism of the ACE gene was related to IMT,but not to internal diameter,distensibility and stiffness of the carotid in Chinese hypertensive subjects. ACE gene polymorphism was a main risk factor for increased carotid IMT. These results may imply that there is a link between lipid metabolism and ACE genotype polymorphism in Chinese hypertensive subjects.